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Subject: Re: Congratulations to Rebel Century

Author: Dave Gomboc

Date: 21:50:12 10/04/99

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On October 04, 1999 at 22:28:36, Robert Hyatt wrote:

>On October 04, 1999 at 18:51:55, Ed Schröder wrote:
>
>>>Posted by Robert Hyatt on October 04, 1999 at 09:35:17:
>>
>>>>Then tell me the difference between a "positional sacrifice", and a
>>>"sacrifice".
>>>
>>>
>>>Here is how _I_ differentiate between the two:
>>>
>>>positional sacrifice:  giving up material for some positional compensation
>>>that you believe will enable you to win when the game seems to be pretty
>>>even, or will enable you to draw if your opponent seems to be winning.  IE
>>>black frequently plays RxNc3 in the Sicilian, as it removes a dangerous piece
>>>and prevents it from supporting the center, plus it often produces other weak-
>>>nesses such as two isolated pawns.  Or where black has pawns at a2/b2/c2 and
>>>black finds a way to play a3 in a position where white must play bxa3.  Black
>>>believes that by giving up the pawn, the three weak white pawns (a2/a3/c2)
>>>will
>>>eventually fall, and because they are isolated, white has no real chances of
>>>winning an endgame on the queenside as well.  All of this is just positional
>>>judgement that says "my position before the sac is worse than my position
>>>after
>>>the sac."
>>>
>>>real sacrifice:  giving up material, not because you see immediate positional
>>>gain that offsets the loss, but because you believe that the resulting
>>>position
>>>has tactical chances that are worth the gamble.  IE the common Bxh7+ move that
>>>gets played even when white can't see a forced mate, but he can see the king
>>>getting into places where it might not be able to avoid a mate.  This is more
>>>speculative since the sacrificer doesn't actually see whether the gamble pays
>>>off or not.  I do this fairly often in blitz time controls myself.  Probably
>>>more often than I do real positional sacrifices...
>>
>>Thanks for pointing out your views.
>>
>>When a human sacs with Bxh7+ he expects a win otherwise he wouldn't
>>play that move. Rebel played 24.gxh6 and Sherbakov took the bait (the
>>white knight) with 24..Qxd5? (24..g6! was the only good move) and then
>>was caught in a heavy king attack. Every annotator will call 24.gxh6 a sac.
>>
>>IMO.
>>
>>Ed
>>
>>PS, just read GM Scherbakov calls 24.gxh6 a sac too :)
>
>
>I realize that.  I am simply pointing out that they are using the term
>_incorrectly_.  IE Howard posted two different author's opinions of what
>makes a sacrifice.  Both agreed that it requires _not_ seeing material gain
>as a result...  in this game hxg6 doesn't sac anything, it wins a bunch.

Obviously it was a sac to GM Scherbakov, then, even if it wasn't a sac to Rebel.
:-)

Dave



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